DB2 Version 10.1 for Linux, UNIX, and Windows

Determining the HADR standby database state

The state that a DB2® High Availability Disaster Recovery (HADR) standby database is in determines what operations it can perform. There are two recommended options for determining the state of the standby: the db2pd command and the MON_GET_HADR table function.

Procedure

To determine the state of an HADR standby database in a primary-standby HADR database pair:

Issue the db2pd command with the -hadr parameter from the primary database or the standby database.
- If you issue the command from the primary database, the command returns a set of data for each standby in your HADR setup.
- If you issue the command from the standby database, the command returns only a single set of data, because the standby is not aware of any other standbys, even if your HADR setup is in multiple standby mode.
Issue a query using the MON_GET_HADR table function on the primary database or the standby database:
```
db2 "select STANDBY_ID, HADR_STATE, from table (mon_get_hadr(NULL))"
```
The following information is returned:
```
  STANDBY_ID HADR_STATE              
  ---------- ----------------------- 
           1 PEER                    
           2 REMOTE_CATCHUP          
           3 REMOTE_CATCHUP          

 3 record(s) selected.
```
- If you issue the query to the primary database, the table function returns a row of information for each standby in your HADR setup.
- If you issue the query to the standby database, the table function returns only a single row of information because the standby is not aware of any other standbys, even if your HADR setup is in multiple standby mode.